Concentration of ores.



UNITED STATES PATENT OFFICE.

ALLEN CRAWFORD HOWARD, OF LONDON, ENGLAND, ASSIGNOR T0 MINERALS SEPA- BATION AMERICAN SYNDICATE (1913) LIMITED, OFLONDON, ENGLAND.

concnnrn'a'rron or cans.

110 Drawing.

To all whom it may concern Be it known that I, ALLEN CRAWFORD HOWARD, a subject of the King of England, residing at 62 London Wall, London, England, have invented certain new and useful Improvements in the Concentration of Ores, of which the following is a specification.

This invention is for improvements in or relating to the concentration of ores and it is particularly applicable to the treatment of copper ores. In this specification the term ores is intended to include concentrates, tailings, slimes and other products containing metalliferous particles.

' This invention refers more'particularly to a modification of the agitation-froth process of concentration, which in its original form as described in the United States Pat-' ent No. 835120 dated November 6, 1906, consists in adding to an ore pulp a small proportion of an oily substance, such as oleic acid, and thereafter agitating the pulp so as to form a froth of the metalliferous particles of the ore, and separating the froth.

Various modifications have been made in the agitation-froth process of concentrating ores as set forth, for example, in the prior Patents Nos. 955012, dated April 12, 1910, 962678, dated June 28, 1910, and 1064723, dated June 17 1913. l

Hitherto froth flotation separation has generally been conducted with the addition of acid to the circuit water, though an alkaline medium or circuit water has been adopted in some cases. For example in the prior British patent No. 11,939, of 1913, the addition of a small proportion of sodium carbonate to the circuit liquors hasv been proposed whereby the lead particles of a mixed zinc lead sulfid ore are floated. In another known processthe addition of a small quantity of" an alkaline substance in certain proportions has been employed to produce a float concentrate. of both lead and zinc sulfids. In these previous processes in which an alkaline circuit has been employed the alkaline substance has always been 1n the form. of a very dilute solution. When treating certain ores, however, the addition of a dilute solution of an alkali to the circuit has been unsuccessful in producing a Specification of Letters Patent.

Patented Oct. 31, 1916.

Application filed May 10, 1915. Serial No. 27,098.

froth of the metalliferous portion of the ore, and 1t has been discovered, in these cases, that the addition of a small proport1on of a concentrated solution of an alkali to the circuit has brought about a good separation.

According tothis invention therefore a process for the separation of the metalliferous particles of an ore consists in submitting the powdered ore to flotation separation w1th agitation and (or) aeration and with or without an organic frothing agent in a circuit to which is added a small proportion of a concentrated solution of an alkali, so as to form a froth of the metalliferous par ticles of the ore, and separating the froth.

The substances which have been found suitable for carrying out the process according to this invention are a concentrated solution of ammonia, caustic soda, or sodium silicate, and the proportions which have been found to produce good results in the treatment of a copper sulfid ore are, with a substantially saturated solution of ammonium hydrate under half a pound to 1 pound per ton of ore, with a substantially saturated solution of caustic soda, half a pound to 1 pound per ton of ore, and with a substantially saturated solution of soda ash or sodium silicate, 1 pound to'2% pounds per ton of ore. It is to be understood, however, that these quantities may be varied without departing from this invention.

One method of carrying this. invention into effect as employed at the mills of the Caucasus Copper Company in the Caucasus, Southern Russia, will now be described. The apparatus employed was that described in the prior United States Patent No. 979857, dated December 27, 1910, and the ground ore, a copper sulfid ore, was passed together with water into the first mixing box, Where a small proportion of the most concentrated solution of caustic soda was added in the proportion of half a pound of a substantially saturated solution per ton of ore. A small proportion of a frothing agent consisting of blast furnace creosote was also added and the mixture was agitated in succeeding boxes in the usual manner to beat in air and produce a froth, the

agitated mixture being then discharged into a spitzkasten where the froth floated. In one test the ore contained 2.37% copper, the concentrates had a grade of 13.88% of copper and gave a recovery of 86.5%. In another test the ore treated assayed 2.42% of copper and the concentrates had a grade of 10.44% of copper and the tailings 0.81% of copper, giving a recovery of 89.8%. In both these examples the addition ofa dilute solution of an alkali even in quantities such that the same amount of alkali was present in the circuit liquor was a failure.

lVhat I claim as my invention and desire to secure by Letters Patent is 1. A process of concentrating ores which consists in adding to an ore pulp a small proportion of an alkali in concentrated form, agitating and aerating the mixture to form a froth, and separating the froth.

2. A process of concentrating ores which consists in adding a small proportion of a concentrated solution of an alkali to an ore pulp, agitating and aerating the mixture to form a froth, and separating the froth.

3. A process of'concentrat-ing-ores which consists in adding to an ore pulp a small proportion of an alkali in concentrated form and a small proportion of a mineral frothing agent, agitating and aerating the mixture to form a froth, and separating the froth.

4. A process of concentrating ores which consists in adding a small proportion of a concentrated solution of an alkali and a small proportion of a mineral frothing agent to an ore pulp, agitating and aerating the mixture to form a froth, and separating the froth.

5. A process of concentrating ores which consists in adding to an ore pulp a small proportion of caustic soda in concentrated form, agitating and aerating the mixture to form a froth, and separating the froth.

6. A process of concentrating ores which consists in adding a small proportion of a concentrated solution of caustic soda to an ore pulp, agitating and aerating the mixture to form a froth, and separating the froth.

7. A process of concentrating ores which consists in adding to an ore pulp a small proportion of caustic soda in concentrated form and a small proportion of a mineral frothing agent, agitating and aerating the mixture to form a froth, and separating the froth.

8. A process of concentrating ores which consists in adding a small proportion of a concentrated solution of caustic soda and a small proportion of a mineral frothing agent to an ore pulp, agitating and aerating the mixture to form a froth, and separating the froth.

9. A process of concentrating copper ores which consists in adding to a pulp of such an ore a small proportion of an alkali in concentrated form, agitating and aerating the mixture to form a froth, and separating the froth.

10. A process of concentrating copper ores which consists in adding a small proportion of a concentrated solution of an alkali to a pulp of such an ore, agitating and aerating the mixture to form a froth, and separating the froth.

11.. A process of concentrating-copper ores which consists in adding to a pulp of such an ore a small proportion of an alkali in concentrated form and a small proportion of a mineral frothing agent, agitating and aerating the mixture to form a froth, and separating the froth. I

12. A process of concentrating copper ores which consists in adding a small pro ortion of a concentrated solution of an alka 1 and a small proportion of a mineral frothing agent to a pulp of such an ore, agitating and aerating the mixture to form a froth, and separating the froth. v

13. A process of concentrating copper ores which consists in adding to a pulp of such an ore a small proportion of caustic soda in concentrated form, agitating and aerating the mixture to form a froth, and separating the froth.

14. A process of concentrating copper ores which consists in adding a small proportion of a concentrated solution of caustic soda to a pulp of such an ore, agitating and aerat ing the mixture to form a froth, and separating the froth.

15. A process of concentrating copper ores which consists in adding to a pulp of such an ore a small proportion of caustic soda in concentrated form and a small proportion of a mineral frothing agent, agitating and aerating. the mixture to form a froth, and separating the froth.

16. A process of concentrating copper ores which consists in adding a small proportion of a concentrated solution of caustic soda and a small proportion of a mineral frothing agent to a pulp of such an ore, agitating and aerating the mixture to form a froth, and separating the froth.

17. A process of concentrating copper ores which consists in adding to a pulp of such an ore a small proportion of caustic soda in concentrated form, and a small proportion of blast furnace creosote, agitating and aerating the mixture to form a froth, and separating the froth.

18. A process of concentrating copper ores which consists in adding a small proportion of a concentrated solution of caustic soda, and a small proportion of blast furnace creosote to a pulp of such an ore, agitating and which consists in adding to a vpulp of such In testimony whei'eof I have signed my an ore a proportion of a concentrated soluname to this specification in the presence of tion of caustic soda amounting to about half two subscribing witnesses.

a pound per long ton of the ore and a small ALLEN CRAWFORD HOWARD. proportion of blast furnace creosote, agitat- Witnesses: ing and aerating the mixture to form a froth, HAROLD CHARLES HAWKINS,

and separating the froth. WILLIAM MAGLEAN. WESON. 

